1. Field of the Invention
The present invention relates to an electronic circuit unit suitable for use in a voltage controlled oscillator and a method of manufacturing the same.
2. Description of the Related Art
Regarding the drawings of the conventional semiconductor device, FIG. 6 is a cross-sectional view of a conventional semiconductor device, and FIG. 7 is a cross-sectional view of a conventional semiconductor device to which external force is applied.
Hereinafter, a configuration of the conventional semiconductor device will be described with reference to FIGS. 6 and 7. A semiconductor bare chip 52 is bonded onto a substrate 51 made of ceramics or the like, and a wire 53 of the semiconductor bare chip 52 is connected to a terminal (not shown) provided on the substrate 51.
A sealing resin 54 made of a soft resin material is coated on the substrate 51 so as to cover the semiconductor bare chip 52 and the wire 53. By coating with the sealing resin 54, moisture resistance of the semiconductor bare chip 52 is secured. At the same time, since the linear expansion coefficient of the sealing resin 54 is greater than that of the wire 53, it is possible to reduce stress of the semiconductor bare chip 52 or the wire 53 and to prevent the wire 53 from breaking by using the soft sealing resin 54.
An overcoat film 55 made of a material harder than that of the sealing resin 54 is formed on a portion of the outer surface of the sealing resin 54 so that when external force is applied to the overcoat film 55, cracks are easily generated on the overcoat film 55 (for example, see Patent Document 1).
The overcoat film 55 made of the material harder than that of the sealing resin 54 is provided on the sealing resin 54, but is cracked when external force is applied in the direction of the arrow A, as shown in FIG. 7. As a result, breaking of the wire 53 is easily detected.
Therefore, the overcoat film 55 not only fails to protect the wire 53 and causes breaking of the wire 53 when external force is applied, but also, even if the semiconductor device is mounted on a predetermined place by a mounting machine, the overcoat film 55 cracks when adsorption is applied to it by an adsorption unit of the mounting machine. As a result, it is impossible to mount the semiconductor device using the mounting machine.